The doctors, Lisa Schwartz and Steven Woloshin of Dartmouth University’s medical school, call the ad worthy of “an Oscar for misleading statistics.” Here’s an example they use to make their point:

“Imagine a group of 100 women who received diagnoses of breast cancer because they felt a breast lump at age 67, all of whom die at age 70. Five-year survival for this group is 0%. Now imagine the women were screened, given their diagnosis three years earlier, at age 64, but still die at age 70. Five-year survival is now 100%, even though no one lived a second longer.”

As for harm, the doctors note that up to 50 percent of women screened annually for a decade “experience at least one false alarm requiring a biopsy.” They add: “For every life saved by mammography, around two to 10 women are overdiagnosed. Women who are overdiagnosed cannot benefit from unnecessary chemotherapy, radiation, or surgery. All they do experience is harm.”

Komen responded with a statement that says, among other things: “The numbers are not in question. Early detection allows for early treatment, which gives women the best chance of surviving breast cancer.”